1. Field of the Invention
The present invention relates to a power source control circuit module including a plurality of regulators.
2. Description of the Related Art
Currently, circuit modules used for portable electronic devices are requested to densify circuit elements. Therefore, as illustrated in Japanese Unexamined Patent Application Publication No. 2005-235808, generally, such a circuit module includes a laminated body, in which a plurality of dielectric layers including electrode patterns are laminated, and a mount type electronic component mounted on the laminated body.
Incidentally, such circuit modules also include a power source control circuit module. The power source control circuit module includes various kinds of regulators, and converts electric power, supplied from an alternating-current power source or a direct-current battery, into a voltage or a current according to the power specification of an output destination (for example, a communication control module or a display control module) and outputs the voltage or current.
FIG. 10A is a side view illustrating the arrangement of individual regulator devices in a power source control circuit module of the related art, and FIG. 10B is a diagram illustrating the rough shape of the pattern of an internal ground electrode in the power source control circuit module of the related art.
A power source control circuit module 10P of the related art includes a laminated body 20P, switching regulator devices 31, and a linear regulator device 32. In the laminated body 20P, dielectric layers 201P, 202P, 203P, 204P, and 205P are sequentially laminated. An internal ground electrode 221P is formed in an interface between the dielectric layers 202P and 203P of the laminated body 20P, and an internal ground electrode 222P is formed in an interface between the dielectric layers 204P and 205P thereof. The plural switching regulator devices 31 and the linear regulator device 32 are mounted in the surface of the laminated body 20P (the surface of the dielectric layer 201P). The ground terminal of each of the plural switching regulator devices 31 is connected to the internal ground electrode 221P through a conductive via hole 231P. The internal ground electrode 221P is connected to the internal ground electrode 222P through a conductive via hole 241P. The internal ground electrode 222P is connected to an external ground connection terminal 211P formed in the back surface of the laminated body 20P, through a conductive via hole 251P.
In this way, in the power source control circuit module 10P of the related art, the plural switching regulator devices 31 and the linear regulator device 32 are connected to the same internal ground electrode 221P, and individual devices are arranged with a given distance DP therebetween so that a noise generated in the switching regulator device 31 is not propagated to the linear regulator device 32. If individual devices are arranged with a distance therebetween that is shorter than the distance DP, it is likely that, owing to interference due to a noise between the switching regulator devices 31 and interference due to a noise from the switching regulator device 31 to the linear regulator device 32, it becomes difficult for the power source control circuit module to stably control an output voltage.
Therefore, in the power source control circuit module 10P of the related art, it is necessary to maintain this distance DP. Therefore, the miniaturization of the laminated body 20P is not easy, and the miniaturization of the power source control circuit module 10P including the laminated body 20P is also not easy.